Double Clutch Transmission system becomes more and more popular in vehicles because of the fuel saving performance, cost efficiency and comfortable feeling during gear change. To save fuel consumption and reduce CO2 emissions, pump can be driven by an electric motor for oil pressure on demand. This paper will introduce a technical solution for sensorless control of an electric pump motor used in a DCT system. Oil pressure control is fulfilled by a speed controller of the oil pump motor. Some critical control requirements for the pump motor are short and reliable start-up stage, stable and accurate speed control. This paper will elaborate on the difficulties of oil pump sensorless control, and how to solve these difficulties with minimum electronic hardware. Test results will be presented. In conclusion, the proposed sensorless control strategy can meet application requirements and meanwhile provide a cost-effective and motor parameters-independent control solution.